Transparent blends of polymethylmethacrylate and certain styrene copolymers

Abstract

Innately-transparent, polymethylmethacrylate polyblends, and transparent shaped articles therefrom fabricated, are comprised with components therein of: (a) polymethylmethacrylate; and (b) at least one copolymer of styrene (and/or equivalent vinyl aromatic monomers) with one or more of certain vinyl acids; plus and optionally or as an alternative; (c) at least one mass-made acrylonitrile-butadiene-styrene or acrylonitrile-butadiene-styrene-type resin in addition to or in replacement of and substitution for said component (b).

What is claimed is: 
     
       1. Polyblended, organic thermoplastic polymers composition, transparent in visual perception by the unaided human eye, said composition being particularly characterizable in having a light absorbance value in the 640 nanometer wave length that is not greater than about 0.12 by standard test when said composition in a solid, shaped specimen form that has an at least substantially uniform thickness which at least approximates 10 mils is disposed and exposed perpendicularly to the path of a ray of said 640 nanometer wavelength light from a source thereof,   said composition comprising, in intimate, thoroughly physically interdispersed admixture:   (a) polymethylmethacrylate in an effective, substantial quantity as an indispensable essential component in said polyblended composition; plus   as additional polyblended component(s) in admixture with said polymethylmethacrylate component (a), a polymeric complement of:   (b) from 1 to about 99 weight percent, based on total composition weight of a copolymerizate of an alkenyl aromatic monomer and a monomeric vinyl acid containing polymerized in the copolymer molecule between about 95 and about 50 weight percent of the alkenyl aromatic monomer,   said alkenyl aromatic monomer being of the Formula: ##STR7## wherein G is selected from the Group consisting of hydrogen and methyl and Ar is an aromatic radical including alkyl and halo-ring-substituted aromatic units of from 6 to about 10 carbon atoms,   said vinyl acid monomer being selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid and mixtures thereof; and   (c) from 0 to 70 weight percent of a mass-made acrylonitrile-butadiene-styrene-type resin that comprises:   from about 14 to about 28 parts by weight of a cyanoalkene of the Formula: ##STR8## wherein R is selected from the Group consisting of hydrogen and a lower alkyl unit containing not more than about 4 carbon atoms therein;   from about 86 to about 72 parts by weight of an alkenyl aromatic monomer of the Formula (I); and   between about 5 and about 18 weight percent of a natural or synthetic rubber ingredient, said rubber ingredient being in the form of particles having a weight average diameter range of from about 0.3 micron to about 5 microns having occluded styrene-acrylonitrile polymer therein;   with the formulation limitations attendant said polyblend composition that:   (i) when there is no quantity of component (c) in the polyblended composition, the weight percent of said component (b) therein present is at least about 1; and   (ii) when both said component (b) and component (c) are present in the polyblended composition, the weight percent of said component (b) therein present is at least about 1 and the weight percent of said component (c) therein present is at least about 20.   
     
     
       2. The polyblended composition of claim 1, wherein the said component (b) compolymerizate contains at least about 75 weight percent of the Formula (I) monomer therein polymerized. 
     
     
       3. The polyblended composition of claim 1, containing at least about 10 weight percent of said interblended polymethylmethacrylate component (a). 
     
     
       4. The polyblended composition of claim 1, containing at least about 20 weight percent of said interblended polymethylmethacrylate component (a). 
     
     
       5. The polyblended composition of claim 1, containing at least about 40 weight percent of said interblended polymethylmethacrylate component (a). 
     
     
       6. A composition in accordance with claim 1 wherein said Formula (I) monomer is styrene. 
     
     
       7. A composition in accordance with claim 1 wherein the acid monomer is acrylic acid. 
     
     
       8. A composition in accordance with claim 1 wherein: said component (c) is present in the composition;   said Formula (I) monomer is styrene;   said Formula (II) monomer is acrylic acid;   said Formula (III) monomer is acrylonitrile; and   said rubber ingredient in component (c) is polybutadiene.   
     
     
       9. A composition in accordance with claim 1 wherein: said component (b) is present in the composition; and   said component (b) is a copolymer of styrene and acrylic acid.   
     
     
       10. A transparent shaped article fabricated from a composition that is in accordance with the compositions of claim 1. 
     
     
       11. A transparent shaped article fabricated from a composition that is in accordance with that of claim 6. 
     
     
       12. A transparent shaped article fabricated from a composition that is in accordance with that of claim 7. 
     
     
       13. A transparent shaped article fabricated from a composition that is in accordance with that of claim 8. 
     
     
       14. A transparent shaped article fabricated from a composition that is in accordance with that of claim 1.